The invention relates to improvements in methods of and in machines for making rod-shaped smokers' products, especially to improvements in methods of and in machines for making filter tipped smokers' products, such as filter cigarettes, cigars or cigarillos. For the sake of simplicity, the following description will refer to filter cigarettes with the understanding, however, that the method and machine can be used with equal or similar advantage for the making of other filter tipped smokers' products.
It is known to make filter cigarettes in a so-called filter tipping machine (typical examples of such machines are those known as MAX and MAX S which are distributed by the assignee of the present application) wherein plain cigarettes of double unit length are subdivided into pairs of coaxial plain cigarettes of unit length, a filter mouthpiece of double unit length is placed between each pair of plain cigarettes of unit length to form therewith a group of three coaxial rod-shaped articles, and the articles of each group are thereupon connected to each other by adhesive-coated uniting bands each of which is convoluted around the respective filter mouthpiece of double unit length and around the adjacent inner end portions of the corresponding plain cigarettes of unit length. The resulting filter cigarettes of double unit length are severed midway between their ends so that each such cigarette yields a pair of coaxial filter cigarettes of unit length. One filter cigarette of each pair is torned end-for-end to ensure that the filter mouthpieces of all filter cigarettes of unit length will face in the same direction before the thus obtained single row of filter cigarettes of unit length is admitted into storage or into a packing machine. It is further customary to inspect the filter cigarettes of unit length in order to ascertain the condition of their wrappers and/or to ascertain the density of unattached ends of the respective plain cigarettes. It is also known to provide filter cigarettes with perforations in order to enable atmospheric air to penetrate into the column of tobacco smoke when the filter cigarette is lighted and the smoker draws tobacco smoke into her or his mouth.
Filter tipping machines normally receive plain cigarettes directly from a cigarette rod making machine, e.g., from a machine known as PROTOS which is distributed by the assignee of the present application. As a rule, a cigarette rod making machine (also called maker) turns out a signle continuous cigarette rod which is subdivided into plain cigarettes of unit length of multiple unit length, and the thus obtained cigarettes are then transported to storage or to the filter tipping machine. Certain recent types of cigarette rod making machines are designed to simultaneously produce two parallel cigarette rods which are subdivided by so-called cutoffs so as to yield files of plain cigarettes of unit length or multiple unit length. The plain cigarettes are delivered to filter tipping machines, to storage or directly to packing machines for plain cigarettes.
Commonly owned copending patent application Ser. No. 127,243 filed Dec. 1, 1987 by Peter Schumacher for "Apparatus for changing the direction of transport of rod-shaped articles of the tobacco processing industry" discloses an apparatus which can accept plain cigarettes coming from a maker that turns out two cigarette rods. The apparatus employs orbiting arms which have pairs of flutes for discrete plain cigarettes and deliver plain cigarettes to the peripheral flutes of two discrete drum-shaped conveyors. The cigarettes in the flutes of one of these discrete conveyors are staggered relative to the cigarettes in the flutes of the other conveyor, and the apparatus of Schumacher further comprises an additional conveyor having peripheral flutes which receive cigarettes from both discrete conveyors so that each flute of the additional conveyor contains two coaxial cigarettes. Rotary conveyors of the type disclosed by Schumacher to transport cigarettes in staggered relation to each other are described in commonly owned U.S. Pat. No. 4,051,947 to Schumacher et al.
The aforementioned commonly owned copending patent applications Ser. Nos. 159,122 and 159,216 of Hinz et al. disclose methods of and machines for making filter cigarettes of unit length. This involves simultaneous severing of two rows of plain cigarettes of unit length so that each such cigarette yields a pair of plain cigarettes of unit length, insertion of a filter mouthpiece of double unit length between each pair of plain cigarettes of unit length, conversion of the thus obtained groups of three coaxial rod-shaped articles each into filter cigarettes of double unit length and subdivision of each filter cigarette of double unit length into two coaxial filter cigarettes of unit length. The thus obtained filter cigarettes of unit length constitute a series of formations of four coaxial filter cigarettes each, and such formations must be converted into different formations, particularly into two rows wherein the filter mouthpieces (of unit length) of all cigarettes in each of the rows face in the same direction.